Field of the Invention
The present invention relates to image display apparatuses such as a head-mounted display (HMD) and a projector and relates to image capturing apparatuses such as a video camera and a still camera.
Description of the Related Art
Image display apparatuses each having a display optical system that magnifies an original image formed on an image forming element such as a liquid crystal element and presenting a magnified observation image to an observer and image capturing apparatuses each capturing an object image through an image sensor such as a CMOS sensor are desirable to be compact and have a wide angle of view. Japanese Patent Laid-Open Nos. 10-153748 and 2000-105338 each disclose an image display apparatus using as a display optical system an eccentric prism whose reflective surfaces having optical powers are eccentrically arranged.
Realizing a compact image display apparatus and a compact image capturing apparatus each having a wide angle of view requires increasing a magnification of their optical system by forming an intermediate image inside the optical system. The image display apparatus disclosed in Japanese Patent Laid-Open No. 2000-105338 forms an intermediate image inside one eccentric prism.
However, the image display apparatus disclosed in Japanese Patent Laid-Open No. 2000-105338 only provides an insufficiently wide angle of view (horizontal and vertical angels of view are respectively about 30° and about 23°), and therefore it is desirable to increase the angle of view while preventing an increase in size of the optical system (eccentric prism). Moreover, a presented image and a captured image are necessary to be high quality images that have no image lack and whose aberration is sufficiently corrected.